What worried me most was togo abroad alone

It is said that this is the biggest lab ________ they have ever built in their school.

The book which ________ at the end of last year turned out to be a great success in Shanghai. [ ]

Did you know that there were ________ visitors in Luoguo Xiang in Beijing last week

I’m worried about the coming test. —You should work hard for it,_____you’ll have to take it again.